ed448-goldilocks: bump ed448 dependency to v0.5 (#1757)

The `ed448` crate provides an `ed448::Signature` type along with generic
PKCS#8 support.

Release PR: RustCrypto/signatures#1335

Author: tarcieri

Cargo.lock

@@ -23,7 +23,7 @@ sha3 = { version = "0.11", default-features = false }
 subtle = { version = "2.6", default-features = false }
 
 # optional dependencies
-ed448 = { version = "0.5.0-rc.6", optional = true, default-features = false }
+ed448 = { version = "0.5", optional = true, default-features = false }
 serdect = { version = "0.4", optional = true }
 signature = { version = "3", optional = true, default-features = false, features = ["digest", "rand_core"] }